1. Field of the Invention
The present invention generally relates to seed planters and more specifically to an attachment for pneumatic seed planters in which a multiple of rows are planted simultaneously during a single pass of the planter. The attachment of the present invention enables selected rows to be shut off by preventing seeds from being discharged in a particular row or rows such as when planting in overlapping rows which occurs when making a final pass with the planter when planting at the edge of a field. The attachment in one embodiment includes a plurality of manually positioned seed release wheels and in another embodiment includes a plurality of solenoid positioned seed release wheels which release the pneumatic pressure associated with a pressurized drum having holes aligned with the number of rows the planter will plant to selectively prevent seed from being discharged into selected tubes which lead to the planting shoes.
2. Description of the Prior Art
Pneumatic seed planters are well known and have been commercially developed. The following U.S. patents relate to this type of planter.
U.S. Pat. No. 3,848,552 PA1 U.S. Pat. No. 3,964,693 PA1 U.S. Pat. No. 4,159,064 PA1 U.S. Pat. No. 4,239,126 PA1 U.S. Pat. No. 4,280,419
One type of pneumatic planter that is currently being marketed contains a pneumatic seed delivery system which includes a pneumatically pressurized drum having a plurality of peripherally arranged rows of holes corresponding with the number of rows the planter is capable of planting. A regulated quantity of seed is placed in the bottom of the drum which is rotated and as the drum rotates, the pneumatic pressure forces seed into the holes which are sufficiently small to prevent passage of the seed but enables passage of air in order that the air pressure will hold the seeds in the holes as they are carried toward the top of the drum. At the top of the drum or at some point above the quantity of seed in the bottom of the drum, seed release wheels engage the drum and release the pressure holding the seed in the holes thus dropping the seed into a manifold of air tubes communicating with the planting shoes with air pressure moving the seed through the manifold and tubes to the corresponding rows being planted.
When planting a row crop such as corn in a typical situation, in a 160 rod or 1/2 mile field with an 8 row planter, during the last pass of the planter at the edge of the field, there is only room for 2 additional rows to be planted thus requiring that 6 rows be overlapped since existing planters do not include any capability of shutting off the unnecessary rows. Thus, the existing procedure wastes the seed and, by overpopulating the overlapped rows, the crop yield is reduced. Based on current prices, the waste in seed corn may be as high as about $25.00 and the loss in yield may be as much as 25 bushels or approximately $50.00 thus resulting in an unnecessary expenditure of about $75.00 when planting this size field.
The prior art does not disclose any structure capable of selectively shutting off seed to selected rows to eliminate seed waste and reduce loss in yield which occurs when planting overlapped of rows of seed.